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First post, by RossBoylan

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DosBox 0.74-3 downloaded today on MS Windows 10 Home 64 bit, version 1903 build 18362.476. Hardware info at the very bottom.

When I run dosbox I get high CPU usage associated with sound, even after disabling (I think) all the sound options.
Originally I had 2 copies of the waves maxxaudio service using 25% of cpu each. Apparently this is a problem other (non-dosbox AFAIK) users on dell have run into: https://www.dell.com/community/Windows-10/Wav … U/td-p/5073273/.
As suggested there I disabled the service. I had to restart to get it out of the way.

However, I now have milder problem: "Windows Audio Graph Isolation" shows as about 7% CPU (all CPU % are as reported by task manager) when dosbox is running--even if no program is running within dosbox. Exiting dosbox eliminates that useage, or at least reduces it to a very low level.

Here's my configuration:

# This is the configuration file for DOSBox 0.74-3. (Please use the latest version of DOSBox)
# Lines starting with a # are comment lines and are ignored by DOSBox.
# They are used to (briefly) document the effect of each option.

# fullscreen: Start dosbox directly in fullscreen. (Press ALT-Enter to go back)
# fulldouble: Use double buffering in fullscreen. It can reduce screen flickering, but it can also result in a slow DOSBox.
# fullresolution: What resolution to use for fullscreen: original, desktop or fixed size (e.g. 1024x768).
# Using your monitor's native resolution (desktop) with aspect=true might give the best results.
# If you end up with small window on a large screen, try an output different from surface.
# On Windows 10 with display scaling (Scale and layout) set to a value above 100%, it is recommended
# to use a lower full/windowresolution, in order to avoid window size problems.
# windowresolution: Scale the window to this size IF the output device supports hardware scaling.
# (output=surface does not!)
# output: What video system to use for output.
# Possible values: surface, overlay, opengl, openglnb, ddraw.
# autolock: Mouse will automatically lock, if you click on the screen. (Press CTRL-F10 to unlock)
# sensitivity: Mouse sensitivity.
# waitonerror: Wait before closing the console if dosbox has an error.
# priority: Priority levels for dosbox. Second entry behind the comma is for when dosbox is not focused/minimized.
# pause is only valid for the second entry.
# Possible values: lowest, lower, normal, higher, highest, pause.
# mapperfile: File used to load/save the key/event mappings from. Resetmapper only works with the defaul value.
# usescancodes: Avoid usage of symkeys, might not work on all operating systems.


# language: Select another language file.
# machine: The type of machine DOSBox tries to emulate.
# Possible values: hercules, cga, tandy, pcjr, ega, vgaonly, svga_s3, svga_et3000, svga_et4000, svga_paradise, vesa_nolfb, vesa_oldvbe.
# captures: Directory where things like wave, midi, screenshot get captured.
# memsize: Amount of memory DOSBox has in megabytes.
# This value is best left at its default to avoid problems with some games,
# though few games might require a higher value.
# There is generally no speed advantage when raising this value.


# frameskip: How many frames DOSBox skips before drawing one.
# aspect: Do aspect correction, if your output method doesn't support scaling this can slow things down!
# scaler: Scaler used to enlarge/enhance low resolution modes. If 'forced' is appended,
# then the scaler will be used even if the result might not be desired.
# To fit a scaler in the resolution used at full screen may require a border or side bars,
# to fill the screen entirely, depending on your hardware, a different scaler/fullresolution might work.
# Possible values: none, normal2x, normal3x, advmame2x, advmame3x, advinterp2x, advinterp3x, hq2x, hq3x, 2xsai, super2xsai, supereagle, tv2x, tv3x, rgb2x, rgb3x, scan2x, scan3x.
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# core: CPU Core used in emulation. auto will switch to dynamic if available and
# appropriate.
# Possible values: auto, dynamic, normal, simple.
# cputype: CPU Type used in emulation. auto is the fastest choice.
# Possible values: auto, 386, 386_slow, 486_slow, pentium_slow, 386_prefetch.
# cycles: Amount of instructions DOSBox tries to emulate each millisecond.
# Setting this value too high results in sound dropouts and lags.
# Cycles can be set in 3 ways:
# 'auto' tries to guess what a game needs.
# It usually works, but can fail for certain games.
# 'fixed #number' will set a fixed amount of cycles. This is what you usually
# need if 'auto' fails. (Example: fixed 4000).
# 'max' will allocate as much cycles as your computer is able to
# handle.
# Possible values: auto, fixed, max.
# cycleup: Amount of cycles to decrease/increase with keycombos.(CTRL-F11/CTRL-F12)
# cycledown: Setting it lower than 100 will be a percentage.


# nosound: Enable silent mode, sound is still emulated though.
# rate: Mixer sample rate, setting any device's rate higher than this will probably lower their sound quality.
# Possible values: 44100, 48000, 32000, 22050, 16000, 11025, 8000, 49716.
# blocksize: Mixer block size, larger blocks might help sound stuttering but sound will also be more lagged.
# Possible values: 1024, 2048, 4096, 8192, 512, 256.
# prebuffer: How many milliseconds of data to keep on top of the blocksize.

# RB the default of false resulted in 2 cores with 25% cpu useage!

# mpu401: Type of MPU-401 to emulate.
# Possible values: intelligent, uart, none.
# mididevice: Device that will receive the MIDI data from MPU-401.
# Possible values: default, win32, alsa, oss, coreaudio, coremidi, none.
# midiconfig: Special configuration options for the device driver. This is usually the id of the device you want to use
# (find the id with mixer/listmidi).
# Or in the case of coreaudio, you can specify a soundfont here.
# See the README/Manual for more details.


# sbtype: Type of Soundblaster to emulate. gb is Gameblaster.
# Possible values: sb1, sb2, sbpro1, sbpro2, sb16, gb, none.
# sbbase: The IO address of the soundblaster.
# Possible values: 220, 240, 260, 280, 2a0, 2c0, 2e0, 300.
# irq: The IRQ number of the soundblaster.
# Possible values: 7, 5, 3, 9, 10, 11, 12.
# dma: The DMA number of the soundblaster.
# Possible values: 1, 5, 0, 3, 6, 7.
# hdma: The High DMA number of the soundblaster.
# Possible values: 1, 5, 0, 3, 6, 7.
# sbmixer: Allow the soundblaster mixer to modify the DOSBox mixer.
# oplmode: Type of OPL emulation. On 'auto' the mode is determined by sblaster type. All OPL modes are Adlib-compatible, except for 'cms'.
# Possible values: auto, cms, opl2, dualopl2, opl3, none.
# oplemu: Provider for the OPL emulation. compat might provide better quality (see oplrate as well).
# Possible values: default, compat, fast.
# oplrate: Sample rate of OPL music emulation. Use 49716 for highest quality (set the mixer rate accordingly).
# Possible values: 44100, 49716, 48000, 32000, 22050, 16000, 11025, 8000.


# gus: Enable the Gravis Ultrasound emulation.
# gusrate: Sample rate of Ultrasound emulation.
# Possible values: 44100, 48000, 32000, 22050, 16000, 11025, 8000, 49716.
# gusbase: The IO base address of the Gravis Ultrasound.
# Possible values: 240, 220, 260, 280, 2a0, 2c0, 2e0, 300.
# gusirq: The IRQ number of the Gravis Ultrasound.
# Possible values: 5, 3, 7, 9, 10, 11, 12.
# gusdma: The DMA channel of the Gravis Ultrasound.
# Possible values: 3, 0, 1, 5, 6, 7.
# ultradir: Path to Ultrasound directory. In this directory
# there should be a MIDI directory that contains
# the patch files for GUS playback. Patch sets used
# with Timidity should work fine.


# pcspeaker: Enable PC-Speaker emulation.
# pcrate: Sample rate of the PC-Speaker sound generation.
# Possible values: 44100, 48000, 32000, 22050, 16000, 11025, 8000, 49716.
# tandy: Enable Tandy Sound System emulation. For 'auto', emulation is present only if machine is set to 'tandy'.
# Possible values: auto, on, off.
# tandyrate: Sample rate of the Tandy 3-Voice generation.
# Possible values: 44100, 48000, 32000, 22050, 16000, 11025, 8000, 49716.
# disney: Enable Disney Sound Source emulation. (Covox Voice Master and Speech Thing compatible).


# joysticktype: Type of joystick to emulate: auto (default), none,
# 2axis (supports two joysticks),
# 4axis (supports one joystick, first joystick used),
# 4axis_2 (supports one joystick, second joystick used),
# fcs (Thrustmaster), ch (CH Flightstick).
# none disables joystick emulation.
# auto chooses emulation depending on real joystick(s).
# (Remember to reset dosbox's mapperfile if you saved it earlier)
# Possible values: auto, 2axis, 4axis, 4axis_2, fcs, ch, none.
# timed: enable timed intervals for axis. Experiment with this option, if your joystick drifts (away).
# autofire: continuously fires as long as you keep the button pressed.
# swap34: swap the 3rd and the 4th axis. Can be useful for certain joysticks.
# buttonwrap: enable button wrapping at the number of emulated buttons.


# serial1: set type of device connected to com port.
# Can be disabled, dummy, modem, nullmodem, directserial.
# Additional parameters must be in the same line in the form of
# parameter:value. Parameter for all types is irq (optional).
# for directserial: realport (required), rxdelay (optional).
# (realport:COM1 realport:ttyS0).
# for modem: listenport (optional).
# for nullmodem: server, rxdelay, txdelay, telnet, usedtr,
# transparent, port, inhsocket (all optional).
# Example: serial1=modem listenport:5000
# Possible values: dummy, disabled, modem, nullmodem, directserial.
# serial2: see serial1
# Possible values: dummy, disabled, modem, nullmodem, directserial.
# serial3: see serial1
# Possible values: dummy, disabled, modem, nullmodem, directserial.
# serial4: see serial1
# Possible values: dummy, disabled, modem, nullmodem, directserial.


# xms: Enable XMS support.
# ems: Enable EMS support.
# umb: Enable UMB support.
# keyboardlayout: Language code of the keyboard layout (or none).


# ipx: Enable ipx over UDP/IP emulation.


# Lines in this section will be run at startup.
# You can put your MOUNT lines here.
mount c C:\Users\ross\DosC
rem c:\xfer\DosProgs\gv.bat

Hardware Dell Inspiron laptop 13-5378. CPU is i5-7200U, 2 cores, 4 logical processors (so I assume 2 processes at 25% actually means both cores are maxed out). 8GB RAM.System info says baseboard manufacture is Dell, product 0XC4P5; maybe that's the motherboard? I don't have any more info about the motherboard.

There is a ton of security software running since I work at a medical center. I'm not seeing any indications they are involved in this problem.

Reply 1 of 7, by leileilol

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DOSBox is strictly for games, not for medical centers (or any professional/industry work). Please do not use DOSBox for any medical profession! It is not an accurate general purpose substitute for the command prompt.


Reply 3 of 7, by DosFreak

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How do you know that the increase in cpu utilization by the process is caused by DOSBox....and why are you worried about it?

Can you try the following and see if there is a difference?
Set your power usage to High Performance Mode
Try DOSBox in Windows Safe Mode
Try Windows built-in sound drivers "High Definition Audio Drivers"

DOSBox Compilation Guides
DosBox Feature Request Thread
PC Game Compatibility List
How To Ask Questions The Smart Way
Running DRM games offline

Reply 4 of 7, by RossBoylan

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DosFreak wrote:

How do you know that the increase in cpu utilization by the process is caused by DOSBox....and why are you worried about it?

The increase in CPU use starts when I launch dosbox and ends when I exit it. It shows up in sound-related processes.

I'm worried about it because it kills performance, heats up the laptop and makes it noisy. This shortens battery life and quite possibly the laptop life. And also it just seems odd that, after I have tried to disable all sound in DOSBox, it's still using the sound system. The problems are less acute after I disable maxx audio, but they are still present. And since Dell shipped the laptop with Maxx Audio, I'm not sure how well the sound system will work without it; some of the problem reports about it mention that sound didn't work well without it.

DosFreak wrote:

Can you try the following and see if there is a difference?

I'm not entirely sure exactly what adjustments the following list refers to: in the dosbox configuration, in the way it is launched, in Windows, or in the bootup.

DosFreak wrote:

Set your power usage to High Performance Mode

I selected "best performance" on the popup from the battery widget. Windows 10 doesn't seem to have a way to select the power mode from the settings dialogue, though it lets you tweak the existing setting and make new power modes (!?). The laptop was plugged in during all tests, including the previous one. The effect of this was to reduce the CPU useage of the sound-related process from ~7% to ~ 3.1-4.6%, usually around 3.5%.

DosFreak wrote:

Try DOSBox in Windows Safe Mode

I looked for options in the "compatibility mode" section of the program properties in Windows Explorer, but didn't find anything that looked like this; the choices were different versions of Windows.

From the name, I suspect this is the option you select at boot time for Windows. I tried hitting F8 on system startup, but have not been able to get a menu that would let me pick safe mode.

DosFreak wrote:

Try Windows built-in sound drivers "High Definition Audio Drivers"

How can I do that?

As noted above, disabling the Maxx Audio gave me something that looks closer to vanilla Windows sound, which resulted in lower but still noticeable CPU useage.

Reply 5 of 7, by Silanda

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I'm seeing this behaviour to an extent too... a very small, and in my case insignificant, extent. CPU usage from "Windows Audio Device Graph Isolation" does indeed increase when DOSBox is active even if no sounds are playing. I'm assuming that DOSBox is always technically outputting audio even if that audio is silence. However, in my case it only increases to about 0.6%, though that's with a hardware sound card and a much stronger processor.

Despite being so small, 0.6% does actually seem on the high side compared to most apps which clock in at 0.2-0.4%. Foobar2000 playing back music using DirectSound pushes it to nearly twice as high as DOSBox at times though.

Reply 6 of 7, by RossBoylan

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The "console" for the DOSBox session suggests it is still doing some audio

DOSBox version 0.74-3
Copyright 2002-2019 DOSBox Team, published under GNU GPL.
CONFIG:Loading primary settings from config file C:\Users\ross\AppData\Local\DOSBox\dosbox-0.74-3.conf
MIXER:No Sound Mode Selected.
MIDI:Opened device:win32

Reply 7 of 7, by RossBoylan

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If I change the config for mididevice to none from default, so


I get no detectable audio cpu useage when I run DOSBox.